Biochemical investigations of cultured amniotic fluid cells in mucolipidosis type IV.

Biochemical abnormalities similar to those observed in cultured fibroblasts of patients with mucolipidosis type IV were demonstrated in cultured amniotic fluid cells of two fetuses affected with mucolipidosis IV. Increased gangliosides and acid mucopolysaccharides were observed in the affected cultures when compared to two normal controls. Both GM3 (monosialo) and GD3 (disialo) gangliosides accumulated in the affected cells: the latter showing a three-fold and the former a two-fold increase over controls. The major mucopolysaccharide components were dermatan sulfate and heparan sulfate, both increased approximately four-fold. A partial, but significant deficiency of soluble ganglioside sialidase was observed in the two affected cultures, while this activity was normal in a culture of a non-affected fetus of the same mother in a third pregnancy. Non-soluble membrane-bound and neuraminlactose sialidase was not affected.